Solid WG draft charter

https://solid.github.io/solid-wg-charter/charter/

Quite an interesting document, mentioned WebID as out of scope

It will be interesting to see what identity system goes through the working
group towards REC states

Perhaps WebID and whatever solid uses for identity can evolve in parallel

WebID CG not currently listed as a coordination group for solid.  So
possibly we'll end up with two webid documents, not sure right now

But good that work is moving towards REC status, imho